Light-sensitive diazotype layers and method of making same



Patented May 4, 1943 UNITED STATE PATEuT LIGHTPSENSITIVE DIAZOTYPE mama- :METHOD OF MAKING SAME flRoelol' Jan Hendrik Alink, Eindhoven, Netherlands, a'ssig-nor, by mesne assignments, to Hartford National Bank and Trust Company, Hartford, Conn., as trustee s No Drawing. Application May 1, 1940, SerialNo. 332,846. In-Germany April 11, 1939 7- Claims. (01.95-7 v a a My invention relates to light-sensitive layers sensitized with a diazonium compound and to a method of making such layers.

The main object of my invention is to provide a simple, inexpensive and reliable method of compound, in the solution. In such cases it is necessary to 'use combinations of diazonium compounds and coloring components which will not react prematurely even in the presence of the organic liquid and I prefer to-use organic liqwater. When the above precautions are taken there is much less'danger of a premature reaction than when one uses a binder which :is soluble in water, such as gelatine.

In carrying out the invention, I prefer to use a. volatileorganic liquid with which it is possible to produce a suspension that can readily be made homogeneous after the suspended material has settled during storage.. Such suspensions can be made in known manner by grinding the material to be suspended with the suspension medi- 11m in a ballmill.

In spite of the fact that the binder of a sensitized 'diazo-layer produced by the method of the invention is insoluble in water, it is possible to produce readily the coloring material necessary for developing the image either in an aqueous medium or by means of a gas, such as ammonia, provided the layer is made in a suitable thickness.

It should be noted that using a thin layer of a binder has the advantage that sharper contrasts and better-defined images are obtained and that to obtain a concentration desirable for the obtainment of sharp contrasts, one is -not limited to the solubility of diazonium compounds and of coloring components, because the use of a suspension according to the invention allows concentration variations within wide limits.

The, method according to the invention has the advantage that it can be carried out in a simplemanner, and it is well adapted 'for use with supports of substantially waterproof mate- -uids whichrhave no, or only a low aflinity,'ior

to several example.

In order that the invention may be clearly understood and readily carried'into efiect Ishall describe the same in more detail with'reference Examplei I I form a suspension by placing 1 'of the ZnClzdouble salt of p-diethylaminobenzenediazonium chloride in its iinely-divided'state and 0.6 gm. of finely-divided phloroglueinein suspension in 100 cc. of carbon tetrachloride in which 5 gins. of cellodammar resin is dissolved.

A layer of this suspension is applied to the 'sur-' face of an aluminium support which is then introduced into a furnace heated to about 80 C. The plate'is moved to and-fro while the solvent is partly evaporated whereupon the excess suspension is poured ofi. Finally the sqlventis completely removed by evaporation An image can now be obtained on the sensitized layer so-iormed by exposing the same until the diazonium compound at the exposed portions thereof has-been completely decomposed and then developing the images by means of gaseous or aqueous ammonia. The resulting black image has a dull appearance which can be made gleaming by spraying the surfacewith a solution of carbon tetrachloride containing 5% cellodammar resin and then re-- moving-.-the carbon tetrachloride .iiyayaporization.

If desired, I may add to the above suspensions a quantity of acid, such as tartaric acid, oxalic acid or the likein order to'avoid the premature production of coloring material. 1

, Example II I form a suspension by placing 4 gm. of finelydivided ZnClajand CdCh-double' salts oip-benzyl ethyl amino benzene 'diazonium chloride in suspension in cos. of trichlorethylene in which 5 gms. of cellodammar resin is dissolved. This suspension is applied to the surface oi. an aluminium plate and the solvent'is removed similarlyto Example I. After exposure according. to image is developed by treating the layer with a solution of 0.5 gm. oi'phloroglucin in liloiccs. of

diluted aqueous ammonia whereby a bluish black' colored positive image is obtained.

It should be noted that the invention extends,

to cases in which a coloring component is not placed in suspension but is dissolved in an organic volatile liquid, such as a solution oi p-naphthol in benzene. In generaLhoWever, the results obtained in this way are inferior to those ob- Example I, the I as glass, acetyl cellulose, rubber, rubber derivatives, such as the product known under the registered trade-mark Pliofllm which is extremely waterproof, paper, or the like.

In addition to binders mentioned abovepsuch as cellodammar resin, I may use binders consisting of materials or mixtures of -materials such as polymerised hydrocarbons, e. g., polystyrol, polymerised esters of unsaturated fatty acid derived for instance, from'acrylic acid and its homologues, vinyl acetic acid or the like, artificial and natural resins and various types of gums such as ester gum, mastic and colophony. As other organic volatile solvents in which the said binders are easily soluble as a rule and which may be used for carrying out the invention, I may mention chlorinated hydrocarbons such as .trichlorethylene and carbon tetrachloride and in addition materials such as benzene, toluene or the like.

r Although I have described my invention with reference to specific examples and applications .I do not desire to'be limited thereto because What 1 claim is:

1. m the manufacture of light-sensitivediazo type material, the steps of applying to the surface of a support a suspension of a diazonium compound in a solution of a water-insoluble binder in a volatile organic liquid in which the diazonium compound is insoluble, and organic liquid.

2. In the manufacture of light-sensitive diamtype material, the steps of applyin to the survolatilizing the face of a support a suspension of a diazonium' 3. In the manufacture of light-sensitive diazotype material, the steps of applying to the surface of a support a suspension of a diazonium compound in a solution of a water-insoluble binder in a volatile organic liquid having substantially no afllnity for water and in which the diazonium compound is insoluble, and removing the organic liquid by volatilization. 4. In the manufacture of light-sensitive diazotype material, the steps of applying to the surface of a support of substantially waterproof material obvious modifications will present themselves to I one skilled in this'art. r

a suspension of a diazonium compound in a solution of a water-insoluble binder in a volatile organic liquid in which the diazonium compound is insoluble, and volatilizing the organic liquid.

5. A diazotype light-sensitive material made by the method of claim 1.

6.' A diazotype light-sensitive material made by the method of claim 2. 1

"1. A diazotype light-sensitive material made by the method of claim 4.

ROELOFVJAN HENDRIK 

